A sub-chronic feeding study of dual toxin insect-resistant transgenic maize (CEMB-413) on Wistar rats.

Genetically modified (GM) crops expressing insecticidal crystal proteins are widely accepted worldwide, but their commercial utilization demands comprehensive risk assessment studies. A 90-day risk assessment study was conducted on Wistar rats fed with GM maize (CEMB-413) expressing binary insect-resistant genes (cry1Ac and cry2Ab) at low (30%) and high (50%) dose along with a control diet group. The study used fifty Wistar rats randomly distributed in five treatment groups. Our study revealed that compared to controls, GM diet had no adverse effects on animal's health, including body weight, food consumption, clinical pathological parameters, serum hormone levels and histological parameters of testes and ovaries of rats. Differences were observed in transcripts levels of fertility related genes, but these were independent of treatment with GM diet.

Evaluation the effect of subchronic feeding of transgenic cotton line (CKC1) on the faecal microbiota of albino rabbits.

Recent studies have demonstrated a strong relationship between the intestinal microbiota and the host health. As such, consumers are increasingly becoming more concerned about the potential effect of certain foods/feeds, particularly of transgenic origin on the gut microbiota. Although the European Food Safety Authority has recommended in their guidelines, to study the effect of transgenic food/feed on host-microbiota, yet, few studies have focused on the evaluation of such effects mainly due to culturing difficulties. Therefore, this study was intended to evaluate the potential adverse effects of transgenic diet consumption on some specific gut microflora (Lactobacillus group, Bifidobacterium genus, Escherichia coli subgroup and Enterococcus genus) of rabbits. A total of forty-eight rabbits were randomly assigned into four groups and fed a diet containing a variable proportion of transgenic cottonseeds at 0, 20, 30 and 40% inclusion level, respectively. Changes in the specific or total faecal bacterial population were monitored at five different experimental stages (i.e. 0, 45, 90, 135 and 180 days) using both the traditional plate count method (TM) and quantitative real-time PCR (qPCR). No significant differences (p > .05) were observed concerning numbers of specific bacteria or total bacteria between the control and experimental groups, though qPCR showed numerically higher values in terms of 16S rRNA gene copies as compared to the values obtained from TM. However, such numerical differences were biologically insignificant (p > .05). Similarly, no significant variations were noticed in the calculated B/E (log10 copies of Bifidobacterium per g faces/log10 copies of E. coli genome per g faeces) ratios in all the groups. All the ratios were in the range of 1.24 to 1.30 throughout the experiment, indicating a good balance of intestinal microflora and greater resistance to intestinal disorders. It is therefore concluded that feeding transgenic cottonseeds could not adversely affect the gut microflora of rabbits during a long-term study.

A 90-day subchronic toxicity study of transgenic cotton expressing Cry1Ac, Cry2A and CP4-EPSPS proteins in Sprague-Dawley rats.

Genetically engineered crops expressing insecticidal and herbicide-tolerant traits offer a new strategy for crop protection and enhanced production; however, at the same time present a challenge in terms of toxicology and safety. The current experiment presents the findings of a 90-day feeding study in Sprague-Dawley rats with transgenic cottonseed which is expressing insecticidal Cry proteins (Cry1Ac and Cry2A), and tolerant to the herbicide glyphosate. There were 100 rats in this experiment divided into 5 groups of 10 rats/sex/group. Cottonseed from transgenic and control (near-isogenic) lines was formulated into standard diets at levels of 10% and 30% (w/w). All formulated diets were nutritionally balanced. Overall appearance, feed consumption, body weight, organ weight, haematology, serum chemistry and urinalysis were comparable between control and treatment groups. In addition, there was no treatment-related difference in findings of microscopic histopathology and gross appearance of tissues. In conclusion, following the 13-week of feeding transgenic cottonseed, no treatment-related adverse effects were observed in any of the parameters measured in this experiment. Thus, this study demonstrated that transgenic cottonseeds do not cause toxicity and are nutritionally equivalent to its conventional counterpart.

Comparative analysis of Constitutive and fiber-specific promoters under the expression pattern of Expansin gene in transgenic Cotton.

Promoters are specified segments of DNA that lead to the initiation of transcription of a specific gene. The designing of a gene cassette for plant transformation is significantly dependent upon the specificity of a promoter. Constitutive Cauliflower mosaic virus promoter, CaMV35S, due to its developmental role, is the most commonly used promoter in plant transformation. While Gossypium hirsutum (Gh) being fiber-specific promoter (GhSCFP) specifically activates transcription in seed coat and fiber associated genes. The Expansin genes are renowned for their versatile roles in plant growth. The overexpression of Expansin genes has been reported to enhance fiber length and fineness. Thus, in this study, a local Cotton variety was transformed with Expansin (CpEXPA1) gene, in the form of two separate cassettes, each with a different promoter, named as 35SEXPA1 and FSEXPA1 expressed under CaMV35S and GhSCFP promoters respectively. Integration and Spatiotemporal relative expression of the transgene were studied in an advanced generation. GhSCFP bearing transgene expression was significantly higher in Cotton fiber than other plant parts. While transgene with CaMV35S promoter was found to be continually expressing in all tissues but the expression was lower in fiber than that expressed under GhSCFP. The temporal expression profile was quite interesting with a gradual increasing pattern of both constructs from 1DPA (days post anthesis) to 18DPA and decreased expression from 24 to 30 DPA. Besides the relative expression of promoters, fiber cellulose quantification and fluorescence intensity were also observed. The study significantly compared the two most commonly used promoters and it is deduced from the results that the GhSCFP promoter could be used more efficiently in fiber when compared with CaMV35S which being constitutive in nature preferred for expression in all parts of the plant.

Assessing the fate of recombinant plant DNA in rabbit's tissues fed genetically modified cotton.

Various feeding studies have been conducted with the different species of animals to evaluate the possible transfer of transgenic DNA (tDNA) from genetically modified (GM) feed into the animal tissues. However, the conclusions drawn from most of such studies are sometimes controversial. Thus, in the present study, an attempt has been made to evaluate the fate of tDNA in rabbits raised on GM cotton-based diet through PCR analysis of the DNA extracted specifically from blood, liver, kidney, heart and intestine (jejunum). A total of 48 rabbits were fed a mixed diet consisting variable proportions of transgenic cottonseeds meal (i.e. 0% w/w, 20% w/w, 30% w/w and 40% w/w) for 180 days. The presence of transgenic DNA fragments (Cry1Ac, Cry2A and CP4 EPSPS) or plant endogenous gene (Sad1) was traced in those specific tissues and organs. The presence of ß-actin (ACTB) was also monitored as an internal control. Neither the transgenic fragments (459 bp of Cry1Ac gene, 167 bp of Cry2A gene and111 bp of CP4 EPSPS gene) nor cotton endogenous reference gene (155 bp of Sad1) could be detected in any of the DNA samples extracted from the rabbit's tissues in both control and transgenic groups. However, 155 bp fragment of the rabbit's reference gene (ACTB) was recovered in all the DNA samples extracted from rabbit tissues. The results obtained from this study revealed that both plant endogenous and transgenic DNA fragments have same fate in rabbit's tissues and were efficiently degraded in the gastrointestinal tract (GIT).

A modified protocol for rapid DNA isolation from cotton (Gossypium spp.).

Extraction of high-quality DNA from Gossypium (Cotton) species is notoriously difficult due to high contents of polysaccharides, quinones and polyphenols other secondary metabolites. Here, we describe a simple, rapid and modified procedure for high-quality DNA extraction from cotton, which is amenable for downstream analyses. In contrast to other CTAB methods, the described procedure is rapid, omits the use of liquid nitrogen, phenol, CsCl gradient ultracentrifugation, uses inexpensive and less hazardous reagents, and requires only ordinary laboratory equipment. The procedure employed the high concentration of NaCl and use of PVP-10 to rid the problems associated with polysaccharides and polyphenols, respectively. The average yield was approximately 10-15 µg of good quality DNA from 100 mg of tissue weight, which is adequate for projects, like genetic mapping or marker-assisted plant breeding. This protocol can be performed in as little as 3 h and may be adapted to high-throughput DNA isolation. •Buffers A and B were redesigned from Paterson et al. (1993) and Porebski et al. (1997), respectively.•Ribonuclease A was added before chloroform extraction.•A simple, rapid and inexpensive DNA extraction method is described.

Effect of dietary supplementation of recombinant Cry and Cp4 epsps proteins on haematological indices of growing rabbits.

Genetically modified (GM) crops expressing insect resistance and herbicide tolerance provide a novel approach for improved crop production but their advent at the same time presents serious challenges in terms of food safety. Although prevailing scientific proof has suggested that transgenic crops are analogous to their conventional counterparts, their use in human and animal diet gave rise to emotional public discussion. A number of studies had been conducted to evaluate the potential unintended effects of transgenic crops expressing single transgene, but very few studies for those with multiple transgenes. As the crops with single and multiple transgenes could impart different effects on non-target organisms, thus, risk evaluation of transgenic crops expressing more than one transgene is required to declare their biosafety. The present study was therefore designed to assess the effects of different levels of dietary transgenic cottonseed expressing recombinants proteins produced by Cry1Ac, Cry2A and Cp4epsps genes on haematological indices of growing rabbits. A total of 48 rabbits were assigned to four dietary treatments containing different levels of transgenic cottonseeds (i.e., 0% w/w, 20% w/w, 30% w/w and 40% w/w) with 0% w/w serving as control. Haematological parameters were measured at periodic intervals (0, 45, 90, 135 and 180) days. No significant (p > 0.05) dose-dependent effects were observed in most of the haematological parameters evaluated. Though, significant differences (p < 0.05) were recorded in the level of MCHC, MCH and HCT in some of experimental male and female rabbits, yet, they were not biologically significant, as all the differences were within the normal reference values. Our study suggested that feeding transgenic cottonseed of up to 40% could not adversely affect rabbit's haematological profile. However, further study needs to be conducted with different cotton genotypes expressing both single and polygenic traits before recommending the utilization of transgenic cottonseed in routine livestock feeding.